Composite system.



0. T. LADEMAN.

COMPOSITE SY$TEM.

APPLICATION FILED 11:12.15, 1909.

1,038,605, Patented Sept. 17, 1912.

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UNITED srArEs PATENT orruon.

OTTO T. LADEMAN, OF MILWAUKEE, WISCONSIN, ASSIGNOR T0 RAILWAY TELEPHONE& ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

COMPOSITE SYSTEM.

Specification of Letters Patent.

Patented Sept. 1'7, 1912.

Application filed February 15, 1909. Serial No. 478,073.

To all whom it may concern:

Be it known that I, O'r'ro T. LADEMAN, citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofVisconsin, have invented a certain new and useful Improvement inComposite Systems, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawings,forming a part of this specification.

My invention relates to composite telephone and telegraph systems, andis more particularly directed to improvements in the telephonic devicesassociated with such circuits. I provide for my invention an improvedarrangement of the telephonic devices in association with telegraphicdevices on a circuit of this character, which, in the form shown,include among other advan tages condensers of different capacity aroundthe different telegraphic devices; likewise, improved means forreceiving a local signal at the telephone, as well as improved means forreceiving the voice currents, and eliminating and cutting down to alarge extent telegraphic noises. 7

My invention further contemplates improved circuit arrangements of thesignal sending circuit at the telephone, so that the telegraphiccurrents will not be at any time in danger of interruption by circuitbreaks in the telephonic instruments.

My invention further contemplates a direct serial inclusion of varioustelephonic sub-station apparatus in the telegraphic circuit, all ofwhich, will more clearly appear hereafter, from the construction andarrangement which I will now describe, in connection with theaccompanying drawing, in which,

Figure 1 illustrates my improved line circuit; Fig. 2, a detail of thetelephonic'ine struments associated with said circuit.

Referring more particularly to Fig.1, I

with short 'circuiting switches 5, 5. The line wire is grounded at 6, 6,at its extremities through the interposition of battery 7, 7, asrequired. Impedance coils88 are included at the extremities of the linewire, immediately beyond where the telephone circuit is designed to cometo an end on said wire 1. To carry the voice currents back over theground or return circuit, condensers 9, 9, are included in the groundc011- tact as shown. These coils modify the abrupt changes of thetelegraphic current. when closing the key, and cause a rounded wave, andthe condensers 9 are enabled to take the discharge. Thus, in dealingwith telegraphic currents in this system, the constants of the devices 8and 9 are so chosen that we may regard thesetclegraphic currents ashaving a wave form, and their fre quency thus comparable to the numberof makes and breaks within ordinary'limits. It is of importance thattelephonic currents be not deflected or impaired by the relays 3, yet itis unwise to have high-capacity condensers bridged around the keys 4,onaccount of excessive sparking. After experimentation, I have foundthat I can place condensers 1010 of low capacity around the key contactswith good results, and em ploy condensers 11, 11, of high capacity,around the telegraphic relays 3. I find that this is a great step inadvancing the talking qualities of a circuit of this character. andtransmission is little, if any, impaired by the telegraphic devices.

The telephonic instrument, which is shown more in detail in Fig. 2, isconnected to-the line wire 1, by means of the switch 12. This telephonicinstrument consists of a receiver 13, arranged in a secondary winding lt, in association with a primary winding 15', which primary andsecondary. wind- 7 ings together have an adjustable core 1.6,

or other suitable means of varying their mutual inductive effects, thusto eliminate to as great an extent as necessary telegraphic impulseswhich might find their way to the receiver 13. The windings 14L and '15,to; gether with the core 16, form a repeating coil, as will be apparent.

The incoming receiver circuit, after pass- 1ng through the winding 15,passes through the conductor 16, the short circuiting spring contactsare not broken until the lower contacts are made, and vice versa, all asis well v understood in the art.

In transmitting, the switch handle 21 is thrown over to its alternateposition, which breaks the contact "of the spring 17, and makes contactbetween the spring 22 and the spring 23, whereby the short circuitaround .the secondary winding of the induction coil is opened, and thetransmitter circuit is closed; Thus, when talking into the telephonethrough the transmitter 25, there are included in circuit with saidtransmitter, the battery 26, the primary 27 of the induction coil, theswitch hook 19, and the conductor 28. Voice currents are thentransmitted through the secondary winding 24 serially over the linecircuit 1, the switch-hook being in the position shown. It will beapparent from this that the local transmitter circuit and the secondarywinding of the induction coil are eliminated from the talking circuitwhen receiving communi cations by means of the receiver 13. The localsignal-recelving circuit contemplates a low wound howler arrangement 29,in association with secondary winding 30, which is inductively relatedwith a primary winding 31. This primary winding 31 makes connection tothe lower contact 32 of the switch hook, and when the switch-hook isdown, brings this winding 31 into serial arrangement with the linewire 1. Telegraphic currents passing through the coil 31 do not aiiectthe signal receiving device 29, on account of the inductive arrangement,as shown. V

The signal sendingcircuit at the telephone consists of the local circuitcomprising the battery 32, a primary winding 33 having an armature 34,with a back contact,

37 to start the primary circuit, and atthe same time opens a shortcircuit around the winding 38, and releases the spring 20 of its backcontact. The winding 38, therefore, is

in serial arrangement with the line wires 1 when signaling, and thesignal can be traced from the line wire 1 to the spring 20, the winding38, the switch-hook 19, contact 32, winding 31, back to the line wire 1.It will be noted from this that when the button 39 is in the positionshown, as when no signals are being sent, the receiver being upon itsswitch-hook, telegraphic currents from the line'wire 1 can pass throughthe coil 31, contact 32, switch-hook 19, directly to the spring 20, andback onto the line wire 1. Now, during the signaling, however, thebutton "39 is pressed inwardly, and the spring 20-broken away from itsback contact, and telegraphic currents can still fiow through-theinstruments, and their circuit istraced from the'line wire 1 through thewinding 31, switch-hook 19, winding 38,

back to the line wire 1. It will be seen from this that allot theoperations incident to the use of thetelephone can be carried on withoutaffecting the telegraphic circuit.

While I have herein shown andparticularly described the preferredembodiment of my invention, I do not wish to limit myself to the preciseconstruction and arrangement as herein set forth, but" Having thus setforth its most salient features, what I claim as new and desire tosecure by Letters Patent is 1. A composite system of telegraphy andtelephony comprising a line circuit, telephone instruments associatedwith said cir-' cuit for impressing voice currents thereon, telegraphkeys serially associated with said circuit, low capacity condensersbridged eX- clusively around said keys, telegraph relays also seriallyassociated with said circuit, and high capacity condensers bridgedexclusively around said relays.

2. A composite system ot-telegraphy and telephony comprising a linecircuit, telephone instruments serially associated with said circuit forimpressing voice currents thereon, telegraph keys serially associatedwith said circuit, low capacity condensers bridged exclusively aroundsaid keys, telegraph relays also serially associated with said circuit,and high capacity condensers bridged exclusively around said relays.

'3. A composite system of telegraphy' and telephony comprising a linecircuit, tele graph instruments associated with said circuit, telephoneinstruments also associated with said circuit, a telephone receiverincluded with each telephone, a signaling-cu cuit for each telephoneadapted when in circuit-to permit the passage therethrough oftelegraphic currents, and a local signal inductively associated withsaid signaling circuit, unresponsive to telegraph currents.

LA composite? systemof telephony and telegraphy comprising a linecircuit, telegraph instruments serially arranged on said line circuit,and telephone instruments also I In Witness whereof, I hereuntosubscribe associated with said llne clrcult, each havmy name this 19thday of January A. 1).,

ing a transmitter and induction coil, the 1909. secondary of saidinduction coil being se- OTTO T. LADEMAN. rially included in the linecircuit When Witnesses:

transmitting messages, and being short-circulted when recelvlngmessages.

MAX NV. ZABEL, O. M. NERMIOL. L

Copies of this patent may be obtained for five cents each, by addressingthe Gommissioner of Patents, Washington, D. C.

